1. Field of the Invention
The present invention relates to a mounting structure of a housing, and in particular to an insulated mounting structure for installing a housing which is a main body case of communication apparatus, electronic appliance or the like in an electrically insulated state.
2. Description of the Related Art
There have been proposed several insulated mounting structures using collars made of insulating material, for example, in Japanese Patent Unexamined Publication No. 6-85472.
As an example, FIG. 1 shows an insulated mounting structure of this kind. For example, a communication apparatus for outdoor installation has a housing 1 for composing the apparatus main body, and it is designed to install the housing 1 by supporting with a mounting frame 3 from beneath in the vertical direction. At the housing 1 side, a bracket 2 is provided as the base, and the mounting frame 3 also has a bracket 4 to be coupled with the bracket 2 by tightening together.
The bracket 2 of the housing 1 has a through hole 2a, and a screw hole 4a is provided in the bracket 4 of the mounting frame 3. Coupling of both brackets 2, 4 is achieved by using an upper spacer 5 and a lower spacer 6 provided in the vertical direction, and inserting a mounting bolt 7 through the upper and lower spacers 5, 6 and the through hole 2a of the bracket 2 of the housing 1 side. The upper and lower spacers 5, 6 are formed in a ring form by using an electrically insulating material. In the bracket 4 of the mounting frame 3 side, the mounting bolt 7 is inserted into its screw hole 4a.
However, the insulated mounting structure of the machine housing as shown in FIG. 1 includes the following problems to be solved.
First, when tightening with the mounting bolt 7, by the tightening force, the upper and lower insulating spacers 5, 6 made of soft material may be damaged or broken.
In other problem, when the housing mounting is done by one worker, while positioning the housing 1 to the mounting frame 3 by one hand, the mounting bolt 7 is inserted into plural mounting holes by centering and tightened to couple together by using a proper coupling tool by other hand. Therefore, it is difficult to do installation of the housing 1 which may drop out or fall unexpectedly during the work.